qml主窗口背景渐变

Question

我有这样的想法。我想在 myApp main window.

中使用渐变而不是单色背景

我测试了不同的代码方式，但没有成功。

结果总是一样的。要么背景为纯白色，要么显示黑白渐变（见图）。

你能告诉我正确的做法吗？我需要更暗的东西。此外，也许是其他颜色。但这只以黑白显示所有内容。

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")

/*
Item
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

//totaly not works
Rectangle
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}


//totaly not works
Gradient
{
    GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
    GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
    GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
    GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
    GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
    GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
    GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
}


//malfunction - still show only two colors - black nad white
RadialGradient
{
    anchors.fill: parent
    GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
    GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
    GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
    GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
    GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
    GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
    GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
}


//malfunction - still show only two colors - black nad white
Rectangle
{
    anchors.fill: parent
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}


//Totaly not works
Item
{
    Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

*/


Item
{
    anchors.fill: parent
    RadialGradient
    {
        anchors.fill: parent
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}

}

Answer 1

您必须将 gradientstops 列表应用于视觉项目的 gradient 属性。

要在 Item 内使用矩形，必须指定 Item 的尺寸，默认情况下 Item 的高度和宽度为零。

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")


Rectangle
{
    anchors.fill: parent
    gradient: Gradient
    {
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
    }
}
}

使用径向渐变

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtGraphicalEffects 1.0

ApplicationWindow {
id: window
visible: true
width: 425
height: 850
title: qsTr("myApp")

Item
{
    anchors.fill: parent
     RadialGradient
    {
        anchors.fill: parent
        gradient: Gradient{
        GradientStop {position: 0.000;color: Qt.rgba(1, 0, 0, 1);}
        GradientStop {position: 0.167;color: Qt.rgba(1, 1, 0, 1);}
        GradientStop {position: 0.333;color: Qt.rgba(0, 1, 0, 1);}
        GradientStop {position: 0.500;color: Qt.rgba(0, 1, 1, 1);}
        GradientStop {position: 0.667;color: Qt.rgba(0, 0, 1, 1);}
        GradientStop {position: 0.833;color: Qt.rgba(1, 0, 1, 1);}
        GradientStop {position: 1.000;color: Qt.rgba(1, 0, 0, 1);}
        }
    }
}
}

qml主窗口背景渐变

qml mainwindow background gradient

qt

qml

qmainwindow